Headphones are just one accessory that have become ubiquitous in our distracted world. But they may also be the most deadly.

Two separate incidents occurred across Canada this week wherein young men were killed by trains, reportedly because they could not hear the vehicles approaching.

Jacob Hicks, 16, was killed in Oshawa, Ontario by a train as he crossed the tracks. Though a city bylaw prevents freights from using horns within the town's limits, the train's engineer notes he blew the whistle to try to capture Hicks' attention.

On the same day in Leduc, near Edmonton, Alberta, Daniel McPherson, 19, was hit by a freight town on tracks that lay near biking and walking trails. The RCMP says it was likely he was listening to music at the time, as the train crew sounded the whistle and put on the emergency brake, but failed to stop in time.

While not everyone who walks around with their iPod is at risk, it's important to note the difference volume control can make. In the past decade, hearing loss among adolescents has risen significantly. As the University of Western Ontario's National Centre for Audiology reports, listening to, for example, the noise level of heavy city traffic for a prolonged period of time can cause gradual hearing loss. That, in turn, can prompt one to turn up the volume on their MP3 player. The benchmark test? If you need to shout to be heard over something, then the sound level is too high.

These tragedies are becoming increasingly common as more people listen to music throughout their daily lives. According to journal Injury Prevention, the number of accidents involving pedestrians wearing headphones has tripled in recent years. Though the study noted that limitations could include a prominence in the media on reporting such accidents versus non-fatal incidents, these two recent cases demonstrate that headphones can be a true threat.

Wondering how you can protect your hearing? Check out these tips: